text: The best way to handle this problem is to keep a set of discrete levels at low excitation energies and a set of binned levels at high energies. The set at low energies is supposed to be known and can be taken from databases (for example, the [ENSDF] database, which has information from what has been already measured with the high resolution technique). The set at high energies is unknown and does not overlap with the known part. At the end of this calculation, the whole region of levels inside the Q value window (known and unknown) is binned.
  At this stage of the analysis it is important to know the internal conversion coefficients for the transitions connecting the known levels. The internal conversion coefficient is defined as the number of de-excitations via e− emission over those via γ emission. If internal conversion takes place, the EM multipole fields of the nucleus do not result in the emission of a photon, instead, the fields interact with the atomic electrons and cause one of the electrons to be emitted from the atom. The gamma that would be emitted after the beta decay is missed, and the γ intensity decreases accordingly: IT = Iγ + Ie− = Iγ(1 + αe), so this phenomenon has to be taken into account in the calculation. Also, the x rays will be contaminated with those coming from the electron conversion process. This is important in electron capture decay, as it can affect the results of any x-ray gated spectra if the internal conversion is strong. Its probability is higher for lower energies and high multipolarities.
  One of the ways to obtain the whole branching ratio matrix is to use the Statistical Nuclear Model. This model generates a binned branching ratio matrix from average level densities and average gamma strength functions. For the unknown part, average branching ratios can be calculated, for which several parameterizations may be chosen, while for the known part the information in the databases is used.